id_comment[] is valide code to fetch values from multiple checkboxes as an array. But first: how to name the id of each checkbox id_comment[] isnt valide. And second what value to insert in the "for" attribute of each label?

hi Armand
2 things:
1. each id must be unique, so suggest "id_comment1" "id_comment2"...
2. For input types checkbox and radio , the text label should be to the right of the control, not to the left as you have in the code examples.